Wind turbines are used to produce electrical energy using a renewable resource and without combusting a fossil fuel. Generally, a wind turbine converts kinetic energy from the wind into electrical power. A horizontal-axis wind turbine includes a tower, a nacelle located at the apex of the tower, and a rotor having a plurality of blades and supported in the nacelle by means of a shaft. The shaft couples the rotor either directly or indirectly with a generator, which is housed inside the nacelle. Consequently, as wind forces the blades to rotate, electrical energy is produced by the generator.
Components of the generator located within the nacelle generate significant heat during operation, which in turn, causes the temperature of the nacelle walls and the generator components to increase. When the generator components are heated, the overall efficiency of power generation may be decreased. Therefore, the generator components and the nacelle may be cooled to ensure that the heat does not adversely affect power generation and/or damage the components.
Conventional wind turbines may include one or more cooling devices configured to remove the heat generated during operation of the wind turbine. The cooling devices may include standard heat sinks. Another exemplary cooling device is a cooler top positioned along one side (e.g., the top surface or roof) of the nacelle and including one or more panels partially enclosed by a cover or spoiler to encourage air flow over the panels. The air flowing past the wind turbine cools a second fluid free flowing through the panels, the second fluid being directed to other heat exchangers within the nacelle to remove heat from generator components and the nacelle. To this end, the cooling devices operate without being separately powered to thereby reduce the temperature of the nacelle and the generator components.
Conventional wind turbines may include a heliplatform or helihoist platform (hereinafter collectively referred to generally as a “heliplatform”) adjacent to the nacelle for receiving a helicopter or supplies/personnel hoisted from a hovering helicopter to the heliplatform. The heliplatform includes a platform, a railing surrounding the platform, and a support structure for the platform. As the heliplatform is configured to support workers and/or a helicopter carrying workers, the placement of the heliplatform in relation to the nacelle is typically subject to numerous safety regulations in certain countries. For example, the railing of the heliplatform must conform to a minimum height safety standard. Additionally, the heliplatform (e.g., including the railing) may be required to be the highest point of the wind turbine, excluding the blades. Consequently, the support structure for the heliplatform must position the heliplatform at least coplanar with the highest point of the nacelle or above the nacelle to fully comply with such safety regulations. In conventional wind turbines, the heliplatform is generally positioned at a rear end of the nacelle roof (e.g., opposite to the rotor) to comply with these regulations. However, when a cooling device such as the cooler top is added to a wind turbine, the conventional placement of a heliplatform may no longer comply with safety regulations because the platform and/or railing thereof may be located below the level of the cover or spoiler.
Furthermore, conventional wind turbines may include a crane or winch for moving replacement or new components delivered to the nacelle. For example, the crane or winch may include a service crane operable within the nacelle. However, conventional cranes or winches are typically not operable to move components to or from the heliplatform when the heliplatform is positioned mostly behind the nacelle. In this regard, conventional cranes and winches cannot extend over the heliplatform to move items onto and off of the heliplatform. Accordingly, during significant repair or restoration of the wind turbine, a larger secondary crane may need to be mounted on rails on the nacelle to provide crane operational coverage at the heliplatform as well as the nacelle roof. Mounting and removing this secondary crane is expensive and inefficient because this process adds significant downtime to the repair or restoration of a wind turbine.
Thus, there remains a need for an improved cooler and heliplatform arrangement that addresses these and other shortcomings in conventional wind turbines. Furthermore, there is also a need for an improved crane that addresses these and other shortcomings in conventional wind turbines.